1. Field of the invention
The present invention relates to a touch panel device used in a multi-functional mobile phone or the like and a display method for the touch panel device.
2. Description Related to the Prior Art
Recently, a touch panel device with a touch panel type liquid crystal display or a touch panel type organic EL display has been commonly used as a display device of a multi-functional mobile phone (smartphone). Such touch panel device does not comprise a mechanical keyboard. Instead, an on-screen keyboard composed of button images is displayed on a screen of the touch panel device when text such as an email is inputted. A user touches or taps the displayed button image with a finger to input a character or the like.
When the on-screen keyboard is displayed on the screen of the touch panel device disclosed in WO2008030976 (corresponding to Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2010-503127), the size of each button image is smaller than the size (contact surface size) of a finger touching the on-screen keyboard. The finger used for touch operation covers the button image so that it is difficult to see which button image the finger is actually touching. The button image being touched is displayed larger than the rest of the button images when the user's finger touches the button image. This allows the user to check the button image actually touched.
In the touch panel device disclosed in the WO2008030976, the button image is displayed in the large size after the user's finger touches the button image. The user is allowed to check which button image has been touched, however, error operation such as touching a wrong button image cannot be prevented.